Don't leave me
by highfunctioningtimelordavenger
Summary: World War One AU. Story starts of during Sherlock and Mycroft's childhood but will go onto teenage years in later chapters.
1. Chapter 1

_**This story is set before and during World War One and during Sherlock and Mycroft's childhood and teenage years. **_

_January 6__th__, 1906_

Mycroft Holmes cradled his new baby brother in his arms. The baby lay there quite blissfully and made small gurgling noises. Mycroft smiled down at his brother Sherlock, knowing that one day soon, the two of them could be of on adventures and playing together.

Anna Holmes smiled over at her two sons from her bed. A nurse stood in the corner to keep an eye on the new baby, after taking measurements and weights. The two brothers looked so content in each other's company, and there was Anna worrying that Mycroft would get jealous!

Mycroft gazed into Sherlock's large, inquisitive eyes. They were the colour of the ocean on a sunny day and were full of intelligence, even for a new born child. He had tufts of dark, curly hair on the top of his head and tiny feet and tiny hands. One of those hands reached out and held onto Mycroft's jacket, exploring the feel of wool for the first time. It made Mycroft giggle and Anna looked on proudly.

_7 years later, September 1913 _

A fifteen year-old Mycroft was being chased around their large house by a small Sherlock wearing a huge pirate's hat. Sherlock had been going through a phase where pirates and treasure were the best things ever. Mycroft had handed Sherlock a hand-made map and some clues as to where the treasure was. It was meant to keep Sherlock quiet for at least an hour, but he had found the stash of brightly coloured marbles within five minutes. Sherlock was far too intelligent for his own good!

Sherlock Holmes was smart. It was undeniable. For what the seven year-old lacked in friends and social skills, he made up in brains. He could tell you your whole life story from a single glance (or two, if you were particularly confusing) and it unnerved most people. People weren't really prepared for what the adorable young boy would be about to say about them after their first encounter, but then people accepted that he was a little different and grew accustomed to him telling them every detail of their lives.

"Mycroft, I'm bored!" Sherlock moaned at his older brother. That was Sherlock's main fault; he had the attention span of a fish, unless it was a topic which he took an interest in (namely: pirates, murder, treasure and crime). "Sherlock, not now, I'm busy, go read one of those books mummy bought you yesterday" Mycroft told his brother. Mycroft was up to his ears in homework and revision notes. And to top it all, he had a little brother who expected to be entertained 24 hours a day by his big brother.

Sherlock grumbled at this and stomped out of the room, being sure to slam the door as he went. Mycroft had become so boring now! All he ever seemed to do was read and study. Yes, on occasion, he set up games for Sherlock like the pirate map one, but those were rare and infrequent. Sherlock still absolutely adored his brother, but hid this well with a mask of annoyance and complaint.

Mycroft watched his brother leave the room. He really needed to get new door hinges soon if Sherlock continued to treat his door so badly! Mycroft looked at the door sadly, wishing that he could help his brother and play with him more. But this new school year had already proven tough and he needed all his concentration focused on one thing at a time.

Mycroft had basically raised Sherlock by himself. Their father had left shortly after Sherlock was born, making rare appearances every once in a while. His mother was usually out and busy. She was a relatively famous singer and would have to travel around a lot of the time. During her travels, she left the boys with their housekeeper, Mrs Hudson. Mrs Hudson was an elderly woman with very strong maternal instincts. Her own two children had grown up and left, so she took on the task of looking after the brothers easily. Sherlock had a great amount of respect and adoration for their old housekeeper, often making her read to him before bed whilst snuggled up next to him. She welcomed this affection, it reminding her of her own children in their younger years.


	2. Chapter 2

Sherlock was now eight years-old. His birthday hadn't been a very big affair, although the Holmes family could certainly afford to be extravagant. Only Mycroft and Mrs Hudson had attended and Sherlock was grateful for that. His mother hadn't yet made an appearance, but Sherlock never gave up hope. It was past nine o'clock- Sherlock's bedtime- when he decided to give up on her coming and go to sleep. He snuggled down into the blanket that Mrs Hudson had knitted for his birthday and looked over at his gift from Mycroft. It was a rather small violin. Sherlock wasn't sure what had spurred Mycroft to get him such a gift, but he was touched that his elder brother had gone to the trouble of getting the instrument made to be exactly his size.

Two months after his birthday, mid-March, Sherlock had already mastered the art of playing his violin. At first, the music had been scratchy and had made both Mycroft and Mrs Hudson wince, but now, he could carry a decent tune. Mycroft and Mrs Hudson were made to endure many of Sherlock's private "concerts", but now, they took great pleasure in listening to the young boy play. They both smiled proudly during these events and clapped enthusiastically afterwards.

Sherlock had changed considerably since being an infant. He no longer craved the attention of his brother, now being quite content to sit and read alone in his room. He was rather tall for an eight year-old and very mature. He still had his curly black hair, one of the only features that remained of his baby years, and still had green-blue eyes that sparkled with intelligence. He was rather on the thin side, unlike Mycroft, who got teased relentlessly by Sherlock for this. Mycroft didn't mind the teasing about his weight, but was genuinely concerned about Sherlock's size. He would be sure to keep an eye on what Sherlock was and wasn't eating at meals.

Their mother hadn't visited for three months now. The two boys supposed she was busy and were quite happy to be on their own. Sherlock was rather pleased about this arrangement, for it meant that the only adult left to tell him what not to do was Mrs Hudson, and she often turned a blind eye to Sherlock's antics. This meant that Sherlock could easily fulfil his latest obsession- science.

Sherlock had always been interested in how things worked and helping the human race move forward with new technologies and devices. He was particularly interested in chemistry and different chemical reactions. He had managed to acquire a substantial amount of chemicals and that was enough to keep his expanding brain busy.

It was nearing the summer time and Mycroft had planned to take Sherlock out to the local park to socialise and have a little fun. He could see how bored his little brother was getting, having read through every book in the house (which was quite a large number) and having completed all his experiments. Mycroft still felt bad about leaving Sherlock to entertain himself all day while he did his work, but he'd make it up to him during the summer.

Sherlock was absolutely bored out of his mind and was looking forward to the summer greatly. He and Mycroft were to spend the majority of the time alone as Mrs Hudson was to be given holiday time. He was excited for this, even though it meant giving up his one source of mother-like love for a few weeks. He wondered if Mycroft would still be up to play with him.


	3. Chapter 3

It was nearing the end of July when news of the war had sent people into a panic. The local regiments were recruiting and Sherlock had never seen Mycroft look so worried. "It's okay, you don't have to go." Sherlock said in an attempt to comfort his brother. "But I feel so guilty, just sitting here, and who'd look after you?" Mycroft replied. "Easy, Mrs Hudson will be back!" Sherlock exclaimed. Mycroft thought this over. "Okay, I suppose I could volunteer. It'll be a good adventure Sherlock! I might even get to go abroad!" he said. Sherlock was thinking too. It would be fun to hear of his brother's adventures.

Three days later and Mycroft was all signed up. Sherlock couldn't help but feel a little jealous at the sight of his big brother feeling proud of himself. Mrs Hudson had returned and had congratulated Mycroft, telling him how brave he was. "And who knows, you might even find a girl. Most can't resist a man in a uniform!" she had laughed. Mycroft had been sent to a training camp in the south of England and was constantly writing to the pair he'd left behind at home.

_Sherlock, _he wrote, _I do hope that you're being good to Mrs Hudson. Training's fun and I've made a friend. James, his name is. Anyway, we might be allowed into some proper action in the near future. I don't know why I didn't want to join up before, this is great! Also, goodbye, Sherlock, I hope that everyone's fine and I should be home for Christmas. Save some turkey for me! _Sherlock laughed at the last line, trust his brother to be thinking about food! He was a little jealous, but he was still really proud of his big brother. He hoped that his mother was too, if she knew at all.

After a week, Sherlock had started to really miss his brother. He always turned to Mrs Hudson for comfort, but she wasn't Mycroft. She let the young boy cuddle into her, feeling a little sad as she realised that this child's family had all but abandoned him. Even if it was for a good cause, like Mycroft. At least his brother kept in regular contact with the small boy.

Four weeks after Mycroft's initial departure, Sherlock was beginning to return to his normal, inquisitive self. He soaked up all of the information he could from Mycroft's frequent letters, enjoying hearing about how his new life was going. He was no longer sad, as he knew that he had Mrs Hudson and that his brother had a lot of new friends. He was also no longer jealous, after hearing about the living conditions and how early they had to get up. Sherlock quite enjoyed his bed!

They had received the news that Mycroft was headed for France, an exciting adventure as he put it in his letter. He had stopped writing so frequently, presumably busy. There was still no sign of his mother, so Sherlock had adopted Mrs Hudson as his mother. She was really caring towards the youngest Holmes brother and had vowed to never leave him, unless Mycroft or his mother came home permanently.

Sherlock sat in bed that night, reading about his brother's latest exploit, smiling to himself as he read about his battle with a giant rat. In the end, Mycroft had won, leaving the rat dead. He seemed quite proud of his achievement, which made Sherlock laugh, especially as he'd drawn a small cartoon of himself standing triumphant over the body of a rat.


	4. Chapter 4

It had been three weeks since Mycroft's last update and Sherlock was getting worried. "He's probably just busy, you know what he's like" Mrs Hudson said soothingly. Her heart was breaking as she watched the young boy's eyes fill up with tears and heard his voice shake slightly. "But what if he's not busy! He could be sick!" Sherlock whispered. Mrs Hudson pulled him in to her chest and hugged him, letting him have a good cry onto her dress. "He'll be fine, we've not heard otherwise."

Two days later and a letter had arrived. Sherlock had bounced up and down with glee as he watched the postman approach. He grabbed the letter and opened it. It was just a small update on where he was currently, but it made Sherlock's day.

Sherlock spent the rest of his day going around with a smile on his face. Mycroft was okay! Mrs Hudson was also pleased, if that letter had brought bad news, it probably would have crushed Sherlock. He was already a fragile little thing and he really didn't need anything else to add to his worries.

It was a bright day, and Mrs Hudson decided to take Sherlock out for a walk. The park was nearby and she thought that it would be good for him to hang around other children his age. Sherlock was all for it, grabbing his small shoes and pulling on his plastic raincoat. The war had barely touched Britain so far, so people were just going about their everyday business.

The park was rather busy, so Mrs Hudson sat down on a bench and told Sherlock to go and play. "Off you go, sweetie." She said in her soft voice. Sherlock smiled and ran to join some other boys his age.

"Hello, can I play with you?" Sherlock asked nicely. He'd never seen these boys before, but they looked like they were having fun. "Uh, sure, I'm Tom, by the way" one of the boys said. Tom had messy brown hair and dark eyes. He seemed friendly enough. "And I'm James and this is John." Another boy said. James was confident and loud. Sherlock already didn't like him. Sherlock looked at the boy who was introduced as John. He was considerably smaller than the others and had fair hair and large blue eyes. He looked up at Sherlock and gave a small smile.

"Hello, John, I'm Sherlock, nice to meet you!" Sherlock exclaimed. "Strange name." John said quietly. "I know, I've never met anyone with the same name as me yet! Though, I've met plenty of Johns." _This boy seems like a good acquaintance, I'll have to have him over for dinner sometime. _Sherlock thought. John seemed intelligent and quiet. Sherlock liked that.

"Would you like to come and have dinner at my house, maybe?" Sherlock asked quietly. He didn't want to scare John and certainly didn't want James overhearing and coming too.

John looked up at Sherlock again. The boy was quite a bit taller than John and he found that rather intimidating, but Sherlock had certain warmth inside him, and John could see that the tall boy had a caring and gentle nature. "Alright, what time can I come?" John replied.

"You can come over now, if you'd like, I'll just go and check with my housekeeper." "And I'll ask my mother." John said. Sherlock skipped over to where Mrs Hudson was sitting. He told her all about his new friend and smiled all the way through it. Mrs Hudson also smiled; she'd been watching him interact with the other boys and overjoyed when she saw him make a friend.

"He can come over if he wants, I'll just make more macaroni for you two!" she said. Sherlock was overjoyed and ran to tell John. "I'm allowed to go, nut my mummy wants to know where you live" John said. "Well, I live at 17 Greendale View, see that house over there." Sherlock told John. "Wow, are you rich?" John asked, slightly shocked as to where his new companion came from. "I don't know, well, I suppose my family is rich, but I don't really care too much about money." "Okay, I'll just go and tell my mummy where you live and then can we go together?" "Yes, I'll see you in a minute, John!"


End file.
